1. Field of the Invention
The invention relates to a dental bur adapted to be cooled with a cooling liquid, and more particularly to a water-cooled dental bur having a proximal part for insertion into a drive device and a distal part with a cutting tip, and having an internal water channel which divides into a lateral channel terminating in a water discharge aperture directing cooling water at the cutting tip and an axial channel extending longitudinally through the distal part and terminating in a radial discharge port in the cutting tip.
2. Description of the Prior Art
It is known that the process of drilling and cutting bone with the dental cutting tool known as a "dental bur" creates a great deal of heat. The heat generated by the bur desiccates the bone and causes pain and discomfort to the patient. It is therefore desirable to apply cooling to the bur and the bone during the drilling and cutting process.
It is known from the prior art to provide a water channel in a dental bur, as shown in U.S. Pat. No. 3,393,452, which shows a dental bur having a bore through its shank and through the cutting tip of the bur extending to its distal end for admitting cooling water to the area of the tooth being drilled or cut. This single cooling water delivery means can be inadequate to the task. Burs of such small diameter are often required for drilling and cutting bone. U.S. Pat. No. 5,100,322 shows a water-cooled dental tool which has an internal hollow space and holes cut transversely through the cutting tip of the tool for admitting a stream of liquid or air for cooling the drilling operation. The dental bur according to the last mentioned patent relies on only cooling liquid sprayed against the exterior of the cutting tool, which is often inadequate.
It is accordingly an object of the present invention to provide a liquid-cooled dental bur which does not have the drawbacks of the known dental burs, and which provides effective cooling also for dental burs of quite small diameters.
Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.